uid=KBS,o=lter,dc=ecoinformatics,dc=orgalluid=sbohm,o=lter,dc=ecoinformatics,dc=orgallpublicreadhttps://lter.kbs.msu.edu/datasets/190.emlG.RobertsonMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060US

(269) 760-8364(269)671-2351robert30@msu.edu0000-0001-9771-9895DennisPenningtonMichigan State University

Hickory CornersMIchigan49060US

269-671-2412pennin34@msu.eduLeileiRuanMichigan State University

ruanleilei@berkeley.eduStephenHamiltonMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060

(269) 671-2231(269)671-2104hamilton@msu.edu0000-0002-4702-9017DavidWeedMichigan State University

Hickory CornersMichiganUS

weedd@msu.eduRandyJacksonUniversity of Wisconsin

US

(608)262-1390rdjackson@wisc.edu0000-0002-8033-1250LauraJach-SmithUniversity of Wisconsin

US

lcsmith4@wisc.eduStaceyVanderWulpMichigan State University

3700 East Gull Lake DriveHickory CornersMI49060US

(269) 671-2339(269) 671-2333vanderws@msu.eduprincipal contactLauraJach-SmithUniversity of Wisconsin

US

lcsmith4@wisc.eduoriginal investigatorBrookWilkeMichigan State University

Hickory CornersMichigan49060US

(269) 671-2242wilkebro@msu.edu0000-0001-6746-5206principal contactCarolinaCordovaMichigan State University

US

cordov13@msu.edu0000-0002-4716-127Xprincipal contact2026-03-08

original data source http://lter.kbs.msu.edu/datasets/190

LTERKBSKellogg Biological StationHickory CornersMichiganGreat LakesyieldPrimary ProductionPopulationsInorganic NutrientsDisturbanceOrganic MatterLTER Core Research Areafarmingbiotahttps://apps.usgs.gov/thesaurus/thesaurus-full.php?thcode=15Data in the KBS LTER core database may not be published without written permission of the lead investigator or project director. These restrictions are intended mainly to preserve the primary investigators' rights to first publication and to ensure that data users are aware of the limitations that may be associated with any specific data set. These restrictions apply to both the baseline data set and to the data sets associated with specific LTER-supported subprojects.All publications of KBS data and images must acknowledge KBS LTER support.The areas around the Kellogg Biological Station in southwest Michigan-85.404699-85.36685742.42026542.3910192009-01-012025-12-31Kellogg Biological StationData Managerlter.data.manager@kbs.msu.eduhttp://lter.kbs.msu.edu02vkce854KBS LTERThe GLBRC Switchgrass Nitrogen Rate Experiment, formerly Nitrogen/Harvest, was established in 2008 to examine the effects of nitrogen fertilization and harvest frequency on switchgrass productivity and greenhouse gas emissions. The experiment is located in the southeast corner of the KBS GLBRC Intensive Site and is laid out in a randomized split block design with 8 N fertilization rates (F1-F8; 0, 28, 56, 84, 112, 140, 168, and 196 kg N/ha, respectively) and with 2 original harvest strategies (H1 and H2; 1 vs 2 harvests per year) comprising the split. Plots are replicated in each of 4 blocks (R1-R4) for a total of 8 × 4 = 32 plots for each harvest strategy. Plots are labeled by arrangement within the replicate block (e.g., plot 204 = Block 2, fourth plot from the west) and by N rate treatment (e.g., SWF4 = Switchgrass N rate #4 = 84 kg N/ha). The two harvests per year strategy was terminated after the 2012 harvest; since 2013 all split plots are harvested once in the fall, with yields recorded separately 2013-2022 and combined starting in 2023. See the GLBRC Switchgrass Nitrogen Rate Experiment plot map for current plot layout. Surface soils are sampled every 2-3 years to monitor fertilizer effects on soil pH and to ascertain nutrient and liming recommendations. Surface soils were monitored in 2009-2010 for seasonal changes in soil inorganic N and deep soil cores were taken in 2013 for a specific experiment, but these are not routine measurements. Soil water (leachate) was also collected and sampled throughout the 2009-2021 growing seasons and analyzed for a variety of chemical parameters. Plants are machine-harvested in the fall and dry matter yields recorded. Subsamples of harvested plants are dried, ground, and analyzed for total carbon and nitrogen; remaining plant material is typically archived. Plots are not sampled for aboveground net primary production (ANPP). In the spring,switchgrass stand counts may be performed to monitor for changes in population growth and recruitment. Note that early documentation may also refer to this experiment as GLBRC N Gradient Switchgrass plots. Also note that as of May 2013, plots with an original ‘2 harvests per year’ strategy are separated by a buried one-half meter deep aluminum barrier.Data Managerhttp://glbrc.kbs.msu.edu/protocols/203Ammonium (NH4 ) and nitrate (NO3-) are the predominate forms of inorganic N in soils; their availability affects rates of N transformation, plant uptake, and N leaching. To measure the nutrient pool of NH4 and NO3- in soils, a subsample of a fresh, sieved composite sample is extracted, filtered, and the extract then analyzed using colorimetric techniques. Concentrations of NH4+ and NO3- are typically expressed as element mass of N per gram of dry soil, but conversion to an areal basis is possible if the soil bulk density and sample depth are known. Sampling frequency: Depends on experiment, time of year, and research objective. Soil inorganic N is routinely measured as part of our LTER and GLBRC soil sampling programs.Data Managerhttp://lter.kbs.msu.edu/protocols/33Soil pH is a measure of the hydrogen ion activity in soil solution; high hydrogen activity (low pH) is an index of soil acidity which can affect nutrient availability and plant growth. To measure the pH of fresh soil, duplicate subsamples (15 g fresh weight) from a sieved soil sample are suspended in solution by adding deionized water in a soil:water ratio of 1:2. The pH of the suspension is measured with a glass electrode pH meter standardized with standard buffer solutions of pH 7 and pH 4. Sampling frequency: Depends on experiment, time of year, and research objective. Soil pH is often taken to inform liming recommendations.Data Managerhttp://lter.kbs.msu.edu/protocols/163The hydrochemistry of surface waters and groundwaters is monitored to examine the change in water quality characteristics as water moves through the landscape and the potential of streams and wetlands to retain or remove nutrients that lead to eutrophication. Surface waters are sampled from a variety of streams, lakes and wetlands in the KBS LTER vicinity and groundwater is sampled from two supply wells at the KBS Pond Laboratory. A variety of chemical and physical variables are measured using the methods given in the references listed below. Sampling frequency: Depends on site and time of year; see the datatables linked below for specific sampling sites and dates.Data Managerhttp://lter.kbs.msu.edu/protocols/168The Costech Elemental Combustion System 4010 is an automated combustion analyzer used to determine total carbon and nitrogen in soil and plant samples. This system employees a helium carrier gas to bring combustion gases to a gas chromatographic separation column and thermal conductivity detector. More information about the analyzer can be obtained from Costech Analytical Technologies (26074 Avenue Hall, Suite 13, Valencia, CA 91355 – USA or http://www.costechanalytical.com/) For preparation and analysis of plant material, see https://lter.kbs.msu.edu/protocols/40. For preparation and analysis of soil, see https://lter.kbs.msu.edu/protocols/37.Data Managerhttp://lter.kbs.msu.edu/protocols/148Data Managerhttp://glbrc.kbs.msu.edu/protocols/129To measure the plant total C and N, plant material is oven dried, finely ground, packed in tin foil capsules, combusted in an automated CHN analyzer, and expressed as the percentage of element in dried plant material. Sampling frequency: Depends on experiment and research objective. For example, as part of our sampling program of the LTER Main Cropping System Experiment, C and N are determined annually in plant materials harvested at peak biomass for annual net primary production (ANPP).Data Managerhttp://lter.kbs.msu.edu/protocols/40Soil bulk density is a measurement of the dry mass of soil per unit soil volume (g/cm3) and thus includes the combined volume of solids and pores that may contain gases or water, or both. Bulk density can affect many soil processes, such as water passage, heat transfer, aeration and root growth. It is also a necessary factor to convert mass-based units to area-based units. This protocol describes bulk density analyses associated with deep (1 m) soil cores sampled at approximate 5-10 year intervals to examine changes in soil carbon with depth. Cores are delineated into soil sections and bulk density is determined either by depth interval or by soil horizon (MCSE in 2008). For each core section or interval, dried subsamples are also pulverized and sampled for carbon and nitrogen analysis, and the remainder or a portion thereof is archived. Sampling frequency: Usually every 5-10 years Data Managerhttp://lter.kbs.msu.edu/protocols/110The cropping systems of the GLBRC Biofuel Cropping System Experiment (BCSE) range from annual crops to perennial monoculture grasses and mixed communities. Different sampling methods are needed to measure belowground net primary production (BNPP) in these diverse systems. For annual crops, root biomass is sampled by excavating a single plant (Kellogg Biological Station, KBS) or a known soil area (Arlington, ARL). For perennial crops, root biomass is sampled from ~1 m deep cores and fine root production is estimated from in-growth cores buried at the beginning of the growing season. In general, root sampling occurs at peak biomass, which means physiological maturity for annuals and pre-senescence for perennials.Data Managerhttp://glbrc.kbs.msu.edu/protocols/157Stand counts can be used to evaluate seedling emergence, density, and distribution. We use the Vogel-Masters stand count method (Vogel and Masters, 2001) in herbaceous perennial treatments to measure frequency of occurrence or stand percentages of a single target species (i.e., switchgrass, miscanthus) or of a given growth form (i.e., native grasses). Dividing the frequency of occurrence by the total area examined provides a conservative estimate of plant density (plants/m2). This protocol should be completed annually during the establishment phase.Data Managerhttp://lter.kbs.msu.edu/protocols/175Soil total carbon and nitrogen as well as the ratio of C:N are important attributes of soil fertility. Both total C and N are measured by a combustion method that does not differentiate between organic and inorganic forms of the elements. In most soils, inorganic N is a tiny fraction of total N so total N is synonymous with organic N. Inorganic C, on the other hand, can be a significant portion of total C in soils with carbonate minerals. Extensive testing of KBS surface soils has shown soil inorganic C to be non-detectable; thus total C in KBS surface soils is synonymous with total organic carbon (TOC). However, carbonates may still be present in deep or recently limed soils, which must be tested for inorganic carbon and, if present, the carbonates removed via acid fumigation (described below) prior to total C analysis. Inorganic C can also be analyzed separately via the inorganic C protocol. To measure total C and N, subsamples of dried, finely ground soil are weighed into small foil capsules that are combusted in an automated CHN analyzer that measures the amount of released CO2 and N2 by gas chromatography. Final values are expressed as the percentage of carbon or nitrogen in dry soil. If inorganic C has been confirmed to be absent, removed, or analyzed separately and subtracted, values can be expressed as total organic C. Sampling frequency depends on experiment and research objectives. Since 2001, soils of the LTER Main Cropping System Experiment are analyzed for total C and N as part of the decadal deep soil core (whole profile) sampling program, usually in late fall of wheat years.Data Managerhttp://lter.kbs.msu.edu/protocols/37The composition and cover of canopy-forming plant species in grass, forb and perennial treatments of GLBRC Experiments is determined by the Line-Point Intercept (LPI) method. The LPI procedure consists of lowering a sampling pin or rod through the vegetation at regular intervals along a set of transects in each plot and recording the first plant species intercepted vertically in its path or the type of ground cover if not intercepted by plants. Percent cover for each plant species is calculated as the number of times that species is recorded (a “hit”) divided by the total number of sampling points along the transect. Height of the intercepted plant is also measured to provide information on community structure. Sampling frequency: Once annually at or near maturity of the dominant plant species, typically August-September. Sampling details: Marginal Land Experiment: beginning 2017; Treatments G5-11; 4 transects/plot: 2 in the fertilized portion and 2 in the unfertilized. Method 2 Biofuel Cropping System Experiment: beginning 2018, Treatments G2-10; 3 NS transects per plot, main only. Each transect predetermined distance and direction from the station flags and numbered 1-3 based on the station number. Stop about every 1m to identify and measure first intercepted plant. Method 2 GLBRC Scale-up Experiment: beginning 2018; 4 NS transects stretching the full length of fields L2, L3, M2, M3, M4. Stop about every 5m to identify and measure first intercepted plant. Method 2Data Managerhttp://lter.kbs.msu.edu/protocols/198https://lter.kbs.msu.edu/datatables/234Kellogg Biological Station LTER: Dry Matter Yields (GLBRC081-003)Dry matter yields from machine harvests (~6 inch cutting height) of the Switchgrass Nitrogen Rate Experiment recorded as Mg dry matter per hectare. Dry+Mater+Yields.csvNone291\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/234.csvyearyear of the growing seasonYYYY-MM-DD11987-4-18harvest_datedate the crop was harvestedYYYY-MM-DD11987-4-18treatment_n_rateamount of nitrogen added to the experimental treatmentpoundsPerAcreintegerreplicatereplicate nested within treatmentintegeryield_tons_acredry matter yieldtonsPerAcrerealyield_mg_hadry matter yield megagramsPerHectarerealmoisture_percentcrop percent moisture at harvestgramsPerHectogramrealharvest_strategy# of harvests per year# of harvests per yearplotplot identifierintegercommentssample notessample noteshttps://lter.kbs.msu.edu/datatables/335Kellogg Biological Station LTER: Soil Inorganic Nitrogen (GLBRC088-011)Soil extractable nitrogen (ammonium and nitrate plus nitrate) concentrations in surface soils (0-25 cm) of the Switchgrass Nitrogen Rate Experiment, monitored over the 2009-2010 growing seasons, and reported as mg N per kg dry soil.Soil+Inorganic+Nitrogen.csvNone291\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/335.csvyearyear of the growing seasonYYYY11987-4-18sample_datedate soil was collectedYYYY-MM-DD11987-4-18treatment_nametreatment nametreatment nametreatment_n_rate_kg_haexperimental treatment - nitrogen application ratekilogramsPerHectareintegerreplicatereplicate block nested within treatmentreplicate block nested within treatmentnitrate_mg_kgsoil extractable nitrate plus nitrite, as N, average of analytical replicates, screened for outliers and corrected for soil moisturemilligramsPerKilogramrealammonium_mg_kgsoil extractable ammonium, as N, average of analytical replicates, screened for outliers and corrected for soil moisturemilligramsPerKilogramrealharvest_strategynumber of harvests per yearintegercommentsnotes specific to the data rownotes specific to the data rowhttps://lter.kbs.msu.edu/datatables/501Kellogg Biological Station LTER: Soil pH (GLBRC088-023)Soil pH of surface cores (0-25 cm) from the Switchgrass Nitrogen Rate Experiment taken periodically to evaluate the need for liming. Analytical samples are prepared from field moist soil samples, sometimes in duplicate resulting in two pH measurements per sample.Soil+pH.csvNone291\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/501.csvsample_datethe date the sample was takenYYYY-MM-DD11987-4-18plotplotplotsubplotthe (former) harvest subplotsthe (former) harvest subplotstreatment_n_rate_kg_haN fertilization ratekilogramsPerHectarerealtreatmenttreatment nametreatment namereplicatereplicatereplicateharvest_strategythe number of harvests per yearthe number of harvests per yearpHthe pH measureddimensionlessrealcommentsadditional information that might be of use in interpreting the dataadditional information that might be of use in interpreting the datasubsamplesoil subsampleintegerhttps://lter.kbs.msu.edu/datatables/374Kellogg Biological Station LTER: Plant Total Carbon and Nitrogen (GLBRC091-002)Total carbon and nitrogen content in the switchgrass crop of the Switchgrass Nitrogen Rate Experiment. A subsample of the machine harvested crop is dried, ground, and analyzed for carbon and nitrogen content, reported as a percentage; the remaining subsample is archived.Plant+Total+Carbon+and+Nitrogen.csvNone261\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/374.csvsample_datedate sampledYYYY-MM-DD11987-4-18plotplot identifier integerreplicatereplicate blockintegernumber_harvests_yearnumber of harvests per year integertreatment_n_ratenitrogen fertilization rate of treatment: corresponds to treatment_name.poundsPerAcrerealpercent_carbonpercent carbon of switchgrassgramsPerHectogramrealpercent_nitrogenpercent carbon of switchgrassgramsPerHectogramrealhttps://lter.kbs.msu.edu/datatables/734Kellogg Biological Station LTER: Soil Bulk Density of Deep Cores (GLBRC093-006)Soil bulk density of deep (0-1 m) cores collected from the Switchgrass Nitrogen Rate Experiment in 2013 for Leilei Ruan. Cores were taken from each treatment plot and sectioned into 0-10, 10-25, 25-50, and 50-100 depth intervals.Soil+Bulk+Density+of+Dep+Cores.csvNone361\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/734.csvtreatmentnitrogen rate treatmentnitrogen rate treatmenttop_depthtop depth of core sectioncentimeterintegerbottom_depthbottom depth of core sectioncentimeterintegerhttps://lter.kbs.msu.edu/datatables/458Kellogg Biological Station LTER: Archived Plant Samples (GLBRC096-003)A list of archived plant material from the Switchgrass Nitrogen Rate Experiment. A subsample from the machine harvested crop is dried, ground and archived, and may also be analyzed for total carbon and nitrogen. Note that “Unsorted” indicates that subsamples from harvested switchgrass are not sorted to species and may contain plant material from other species. Also note that the plot label is derived from the following information “treatment name, plot number – original number of harvests per year”. For “SWF1 108-H1”, as an example, SWF1 is fertilization level #1 (0 kg N/ha), 108 is the plot in block #1 that is the eighth from the west, and H1 is the initial harvest strategy of 1 harvest per year.Archived+Plant+Samples.csvNone281\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/458.csvyearyear of the growing seasonYYYY11987-4-18sample_datedate sampledYYYY-MM-DD11987-4-18sample_date_describedsample date in words when multiple dates are combinedsample date in words when multiple dates are combinedsiteexperiment locationexperiment locationtreatmenttreatment of nitrogen applicationtreatment of nitrogen applicationspeciesspecies collectedspecies collectedcommentnotes about the data rownotes about the data rowhttps://lter.kbs.msu.edu/datatables/732Kellogg Biological Station LTER: Root Biomass in Deep Cores (GLBRC130-005)Root biomass in deep cores (0-1 m) collected from the Switchgrass Nitrogen Rate Experiment in 2013 for Leilei Ruan. Cores were taken from each treatment plot and sectioned into 0-10, 10-25, 25-50, and 50-100 depth intervals.Rot+Biomas+in+Dep+Cores.csvNone331\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/732.csvsample_datethe sample datethe sample dateexperimentthe experimentthe experimenttreatmenttreatment of switchgrass nitrogen application treatment of switchgrass nitrogen application plotswitchgrass experimental plotswitchgrass experimental plotdepth_top_cmtop sampling depthtop sampling depthbottom_depth_cmbottom sampling depthbottom sampling depthroot_weightroot weight in the samplegramrealcampaignsampling campaignsampling campaignhttps://lter.kbs.msu.edu/datatables/682Kellogg Biological Station LTER: Switchgrass Stand Counts (GLBRC132_002)Stand counts of switchgrass populations in the Switchgrass Nitrogen Rate Experiment periodically conducted in the spring to assess growth and recruitment. Counts are reported in number of plants per square meter.Switchgras+Stand+Counts.csvNone271\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/682.csvyearyear sampledyear sampledsample_datedate sampledYYYY-MM-DD11987-4-18siteexperiment siteexperiment siteexperimentexperiment nameexperiment nameplotplot sampledplot sampledtreatmenttreatment nametreatment namenitrogen rateannual N fertilization ratekilogramsPerHectarerealaverage_stand_count_m2number of plants per meter squared as estimated by the Vogel and Masters 2001 grid method numberPerMeterSquaredrealhttps://lter.kbs.msu.edu/datatables/723Kellogg Biological Station LTER: Soil Total Carbon and Nitrogen (GLBRC132-003)Soil total carbon and nitrogen in surface (0-25 cm) and deep (0-1 m) core samples from the Switchgrass Nitrogen Rate Experiment. Deep core samples were collected - in 2013 for Leilei Ruan, taken from each treatment plot, and sectioned into 0-10, 10-25, 25-50, and 50-100 depth intervals. - in 2024 for Ashim. Taken from each plot and sectioned into the same depth intervals. Soil+Total+Carbon+and+Nitrogen.csvNone281\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/723.csvsample_datedate when the sample was taken from the fieldYYYY-MM-DD11987-4-18treatmentthe treatment namethe treatment namereplicatethe replicate namethe replicate namesub_plotthe sub plot sampled (H1 = one harvest, H2 = 2 harvests per year until 2012)the sub plot sampled (H1 = one harvest, H2 = 2 harvests per year until 2012)top_depth_cmthe top depth of the soil core takencentimeterrealbottom_depth_cmthe bottom depth of the soil core takencentimeterrealnitrogen_percentthe percent total N by weightdimensionlessrealcarbon_percentthe percent total C by weightdimensionlessrealinternal_plot_namethe internal name of the sample or barcodethe internal name of the sample or barcodehttps://lter.kbs.msu.edu/datatables/744Kellogg Biological Station LTER: Plant N and P from Jach-Smith and Jackson (2020) (GLBRC132-004)Plant nitrogen and phosphorus responses to zero, medium and high nitroen application rates.Plant+N+and+P+from+Jach-Smith+and+Jackson+(2020).csvNone251\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/744.csvyearexperiment yearexperiment yearplotexperiment plotexperiment plotnitrogen_ratenitrogen application ratekilogramsPerHectarerealplant_Nplant nitrogengramsPerHectogramrealplant_Pplant phosphorusgramsPerHectogramrealhttps://lter.kbs.msu.edu/datatables/751Kellogg Biological Station LTER: Stable isotope and hyphal biomass data from Jach-Smith and Jackson (2020) (GLBRC132-005)Stable isotope and AMF hyphal biomass responses to zero, medium and high nitrogen application rates.Stable+isotope+and+hyphal+biomas+data+from+Jach-Smith+and+Jackson+(2020).csvNone281\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/751.csvplotexperiment plotexperiment plotnitrogen_ratenitrogen application ratekilogramsPerHectarerealdelta_N15_plantdelta N15 in plant in per milmicrogramsPerGramrealdelta_N15_availablesoil available delta N15 in per milmicrogramsPerGramrealdelta_N15_fungidelta N15 in AMF in per milmicrogramsPerGramrealhyphae_biomass -g sandAMF biomassmicrogramsPerGramrealhttps://lter.kbs.msu.edu/datatables/754Kellogg Biological Station LTER: Soil nitrogen and phosphorus data from Jach-Smith and Jackson (2020) (GLBRC132-006)Soil nitrogen and phosphorus responses to zero, medium and high nitrogen application rates.Soil+nitrogen+and+phosphorus+data+from+Jach-Smith+and+Jackson+(2020).csvNone281\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/754.csvsiteexperimental siteexperimental sitenitrogen_ratenitrogen application ratekilogramsPerHectarerealtime_pointsampling time_pointsampling time_pointfinal_soil_NO3_Nmeasured NO3-N concentration in solution (ppm)microgramsPerLiterrealfinal_soil_NH4_Nmeasured NH4-N concentration in solution (ppm)microgramsPerLiterrealhttps://lter.kbs.msu.edu/datatables/838Kellogg Biological Station LTER: Decadal deep core CN comparison (GLBRC132-007)Deep core samples were taken from every plot in 2013 and 2024. This datatable is a complication of the deep core CN data from https://data.sustainability.glbrc.org/datatables/723 and https://data.sustainability.glbrc.org/datatables/734Decadal+dep+core+CN+comparison.csvNone321\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/838.csvexperimentthe experiment namethe experiment namesample_datethe date the sample was removed from the fieldYYYY-MM-DD11987-4-18treatmentthe treatmentthe treatmentreplicatethe replicatethe replicatetop_depth_cmthe top depth of the soil core section. Or the average top depth when there were more than one core sampled.centimeterrealcore_length_cmthe average core length of the sections at this depth.centimeterrealbottom_depth_cmthe average bottom depth of the core section(s).centimeterrealcore_diameter_cmthe diameter of the corecentimeterrealbulk_density_gravel_freethe average gravel free bulk density of this core section.gramsPerCubicCentimeterrealtotal_bulk_densitythe average total bulk density for this core sections(s).gramsPerCubicCentimeterrealcarbon_percentthe percent carbon in the samplegramsPerHectogramrealnitrogen_percentthe percent nitrogen in the samplegramsPerHectogramrealsample_nameinternal sample name or barcodeinternal sample name or barcodehttps://lter.kbs.msu.edu/datatables/840Kellogg Biological Station LTER: Canopy species and height (GLBRC132-008)Canopy species composition and height is surveyed at or near maturity of the dominant plant species using the Line-Point Intercept (LPI) . This method is used to quantify changes in dominant plant species by measuring their canopy cover and height. It involves lowering a pin or rod at regular intervals along transects and recording the first plant species intercepted. Percent cover for each species is calculated from the number of hits divided by total sampling points, allowing researchers to track shifts in dominance over timeCanopy+species+and+height.csvNone271\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/840.csvsample_datethe date of the observation YYYY-MM-DD11987-4-18sitethe experiment/sitethe experiment/sitetreatmentthe treatment codethe treatment codereplicatethe replicate plotthe replicate plotspeciesthe species observedthe species observedheightthe height of the species observedcentimeterrealhas_lodgedan observational scoring. True if the plant was considered "lodged"an observational scoring. True if the plant was considered "lodged"commentany comments about the observationany comments about the observationhttps://lter.kbs.msu.edu/datatables/614Kellogg Biological Station LTER: Agronomic Soil Chemistry (KBS078-021)Agronomic soil test results of the Switchgrass Nitrogen Rate Experiment. Surface soils (0-25 cm) are periodically sampled, air dried, and sent to an analytical laboratory (MSU Soil and Plant Nutrient Lab through 2022) for testing and fertilizer and liming recommendations.Agronomic+Soil+Chemistry.csvNone351\ncolumn,no"\https://data.sustainability.glbrc.org/datatables/614.csvsample_datethe date the sample was takenthe date the sample was takensitestudy sitestudy siteexperimentexperimentexperimentplotplotplotharvest_strategy(former) harvest strategy(former) harvest strategytreatmentnitrogen treatment levelnitrogen treatment levelsoil sampling depthdepth of soil samplingdepth of soil samplingest_cecCation exchange capacity in meq/100g soilmilliEquivalentsPerHundredGramrealpHpH value of soil solutiondimensionlessreallime_indexindicator of potential acidityrealp_ppmphosphorus in soilmilligramsPerKilogramrealk_ppmpotassium in soilmilligramsPerKilogramrealca_ppmcalcium in soilmilligramsPerKilogramrealmg_ppmmagnesium in soilmilligramsPerKilogramrealnitrogen_ratenitrogen application ratepoundsPerAcrereallabthe lab that performed the analysisthe lab that performed the analysis